The objective of this proposal is to improve the diagnosis, treatment and outcome of children with cancer through participation in protocols designed by the Children's Cancer Group (CCG). We plan to enter eligible patients on CCG protocols, participate in the development and execution of these protocols, supply materials for and execute biological studies of cancer through CCG, serve as a referral center for other CCG institutions which lack facilities for bone marrow transplantation or for phase I chemotherapy and to perform independent studies which may serve as the basis for future CCG studies. The Children's Hospital Medical Center (CHMC) is the major pediatric medical center in the greater Cincinnati area with a population of 2 million people. CHMC is the only hospital with pediatric inpatient capabilities within a 50 to 75 mile radius of Cincinnati and is one of the largest pediatric medical centers within the United States. There are four medical centers affiliated with CHMC: the University of Kentucky, Lexington, KY; Children's Hospital of Akron, Akron, OH; the Children's Hospital of the Penn State Geiseinger Health System is located in Hershey, PA; and Scottish Rite Children's Hospital, Atlanta, GA. Combined, they serve population areas of another 8 to 10 million people. Together, we have become the largest contributor of patients of CCG studies. With this grant application, we welcome our newest affiliate, Kosair Children's Hospital and the University of Louisville, a long standing CCG member institution which adds another 1 to 1.5 million people to the area we serve. As part of this application the University of Louisville data on past participation is separated from that of the other five institutions. Personnel from CHMC and its affiliates have made many contributions to the administration of the CCG and to its scientific studies. Highlights of this participation include personnel serving as member of the Executive Committee of the CCG, Chair of the AML Strategy Group, and leading study committees. CHMC provides the CCG with one of its oldest and largest pediatric Bone Marrow Transplantation units. This unit has expanded from 8 to 12 beds in the past five years. This unit has been particularly active in transplantation of patients with neuroblastoma, acute myeloid leukemia and brain tumors. CHMC is one of the relatively few phase I institutions adding to the CCG's capability to perform these unique and difficult studies. We have also been the leading contributor to cancer biologic studies, a leading contributor to the Human Tumor Tissue Network and have served as a center for pediatric tumor xenografts which allow completion of additional studies of the biology of these tumors.